Is reusing wastewater a solution for Arizona's water woes?
PHOENIX - As the Southwest continues to deal with a mega-drought and its negative impact on water, officials are looking at various solutions.
On May 1 and May 2, we looked at what San Diego is doing to expand their water source, from desalination to wastewater treatment. We also looked at whether such solutions are feasible for Arizona.
Also Read: As water crisis persists, San Diego looks at treated wastewater as a drinking water source
Phoenix water officials look at transforming wastewater
In The Valley, water officials are planning to turn wastewater into drinking water, just like officials in San Diego did. In less than a decade, such endeavors could become the reality in Phoenix.
It is well-known that the Phoenix area is located in a desert. In the middle of that desert, there is a lush wetland where water flows, ponds are full, and marshland plants are flourishing.
The clear water that cascades into the Salt River did not directly come from nature. The water used to be sewage before it was sanitized at a wastewater treatment plant.
"We don’t actually have wastewater coming into the ponds. That's not what we're talking about. We're talking about water that's come through a bunch of processes, and in the end here, it's getting ready to get discharged to the river," said City of Phoenix Water Services Director Troy Hayes.
If the City of Phoenix’s plans come into fruition, this treated water will become a source of drinking water in the near future. Phoenix water officials envision a brand new, city-run advanced water purification plant that could be built near the current water facility, which is located at 91st Avenue and Broadway.
"We would have a pump station here, which would then pump it into the advanced water purification facility, which would then treat it to drinking water levels, then piped directly into the system," said Hayes.
The water to be treated by the proposed facility is graywater and blackwater.
According to the New Mexico State University, graywater is water that has been used for washing dishes, laundering clothes, or bathing. Blackwater, according to the U.S. Green Building Council, is "wastewater containing urine or fecal matter." Some state or local building codes also consider wastewater from kitchen sinks, showers, or bathtubs as blackwater.
Currently, graywater and blackwater in the Phoenix area travels through the sewer system, and is then pumped into a facility, where it undergoes several stages of solids removal, microbial treatment, further filtering and disinfecting.
The water treatment facility at 91st Avenue and Broadway releases about 230 million gallons of effluent, or treated wastewater, on a daily basis. Some of the effluent goes to the Palo Verde Nuclear Power Plant for cooling, and some goes to agricultural use.
"Over and above that, we think we have about 60 million gallons a day that is released into the river that we think we can turn back into drinking water," said Hayes.
As mentioned earlier, the process of going from sewer water to effluent water, and from there to drinking water, is already happening in other major Western cities. Water officials in Phoenix have a preliminary estimate on the cost to build their own advanced purification water facility: about $1 billion.
"Reverse osmosis, ultra filtration, UV, ozone, all the things you see in the bottled water type industry is what we're talking about implementing at the back end of this water," said Hayes.
Hayes says the proposed advanced purification plant would bring the effluent water up to federal and state drinking water standards, and will be closely regulated.
"We do over five million tests of our drinking water systems now," said Hayes. "We take water quality very seriously."
Phoenix is hoping to partner with several other Valley cities in getting the future purification facility funded, designed, and constructed. Residents could see their wastewater come full circle by 2030.
Dutch firm creates graywater recycling device
Besides solutions on a municipal or county level, water-saving solutions beyond the usual suggestions made by utility companies are also available for homes.
A company called Hydraloop has created a technology that promises to help save water for households by sterilizing and recycling graywater.
In a way, Hydraloop is like having a water treatment facility inside a person's house.
"The gray water now, in a typical plumbing system, all goes down the drain, so we need to reconfigure that. Gray water from bath and showers and sinks, all that is directed to the Hydraloop," said Melissa Lubitz with Hydraloop.
Hydraloop can be installed in a garage, or a utility room inside the house. The device does not use filters or chemicals to clean up gray water.
"It functions on gravity," said Lubitz. "For sedimentation, we inject air for floatation to pull out all the organics. We used a biological reactor to break down the organics with actual live organics, then we use UV disinfection. Typically, the water goes in the top. Then, over a 3-4 hour period, it will go through the treatment. The bottom tank will fill with this treated water."
Hydraloop has installed its gray water recycling systems in South African resorts, as well as homes and businesses in the Middle East and Australia. The firm recently started bring the system to North America, and is currently working with developers on including the system in newly constructed homes.
"These days in the Greater Phoenix Area, reclaimed water is about 12% of the water that is used," said Sarah Porter with the Kyl Center for Water Policy, which is part of Arizona State University. "It's a very important part of cities' plan of making sure to meet demand."
Water policy officials say more than 90% of wastewater is currently reclaimed through wastewater treatment facilities.
"What that system does is change where the water is being recycled, it has water being reclaimed at the residence instead of at the municipal level," said Porter.
The makers of Hydraloop claim its in-home system could potentially save residents money on their water bills, and reduce the amount of water the household takes in.
"The main focus is we’re trying to save potable water usage," said Lubitz.